She had been arrested several times, according to police. She pleaded guilty to assaulting a man in 2003, and drug possession.

Menendez was caught on surveillance video running away from the scene shortly after the incident.

She was arraigned Saturday night on a charge of second degree murder as a hate crime. She was ordered to undergo a psychiatric evaluation and is being held without bail.

“The defendant is accused of committing what is every subway commuter’s worst nightmare,” Queens District Attorney Richard Brown said.

Menendez was incoherent at her arraignment in Queens criminal court, at one point laughing so hard that the judge told her defense lawyer, “You’re going to have to have your client stop laughing.”

Police said Menendez admitted to shoving Sen off the platform.

Menendez reportedly told authorities, “I pushed a Muslim off the train tracks because I hate Hindus and Muslims. Ever since 2001 when they put down the Twin Towers I’ve been beating them up,” according to the criminal complaint.

She later said, “There is no reason. I just pushed him in front of the train because I thought it would be cool,” according to the Queens district attorney’s office.

She was arrested at Empire Boulevard and Bedford Avenue in Crown Heights, Brooklyn on Saturday morning after someone recognized her and called 911, according to police.

Following her arrest Menendez gave investigators two addresses; one in the Bronx, the other in the Forest Hills section of Queens, the apparent home of her mother.

Witnesses said it did not appear the two had any contact before the incident.

Sen, a Bangladeshi native, ran a copy shop on Amsterdam Avenue near Columbia University and shared one floor of a house in Queens with two roommates.

He was Hindu, according to his roommates.

The incident marked the second deadly subway push this month. On Dec. 3, police said 58-year-old Ki Suck Han was pushed to his death by 30-year-old Naeem Davis. The two were seen on cell phone video arguing just moments before Han was dumped on the tracks.